(a)Field of the Invention
The present invention concerns a valve assembly for non-returnable packing or non-rechargeable container, of the type comprising a valve housing including a main valve forced into closing by means of a first return spring, and capable of cooperating with a means of operating the valve against the action of the spring. (b)Description of Prior Art
The increasingly frequent use of light packings which should only be filled once, so called non-returnable packings, raises safety problems with respect to their eventual reuse which is prohibited, especially since, in certain cases, the pressures use can be high.
To remove the possibility of some later filling by a user who is not aware of the law or of the dangers associated with such an operation, the invention proposes a new valve assembly whose structure is simple and compact, of low manufacturing cost, exclusively permitting the initial filling of the packing and preventing without any doubt any new filling subsequent to an at least partial emptying of the packing.